A cycle was a process that occurred in a particular sequence in a continuous loop that ended with similar results each time before starting over again. The duration of time required for a cycle to complete was known a period, while the time between the completion of one cycle and the beginning of the next was known as an interval. The number of occurrences of a cycle over a specific period of time was known as the frequency.

During the USS Enterprise-D visit to Iconia in 2365, the away team, consisting of Jean-Luc Picard, Data and Worf, observed that the destination that appeared in the Iconian gateway repeated. When they learned they were stranded on the planet, the considered using the gateway to return to the Enterprise. When Picard inquired how long the interval was for the Enterprise to appear in the gateway, Worf noted that it was "About four minutes, if the cycle holds." (TNG: "Contagion")

Portions of the planet Bersallis III experienced a period of fire storm activity that happened on a seven year cycle. In 2369 the Bersallin fire storms arrived eight months early, forcing the Enterprise-D to evacuate the Federation outpost there. (TNG: "Lessons")

The relationship between the sun setting and the moon rising was likened by Picard and Worf in discussing the how Masaka and Korgano switched positions, "[l]ike two powerful rulers changing places in a continuous cycle." Deanna Troi then added, "And like the sun and the moon, only one of them can be in ascendance at any given time." (TNG: "Masks")